The invention relates to motorcycle swingarms.
It is known to use a swingarm to interconnect the rear wheel of a motorcycle to the frame of the motorcycle. Typically, the oil for use in the engine of a motorcycle is contained in the crankcase of the engine, or within a separate external oil sump or tank that is mounted to the engine or the frame.
Known motorcycles often include an adjustable rear axle that slides in a slot in the swingarm to adjust the tension in a flexible drive member. The caliper for the rear disc brake assembly is positioned at a fixed distance with respect to the axle and moves with the axle to remain in a functional position relative to a brake rotor.
The present invention provides a motorcycle including a frame and an engine/transmission assembly mounted to the frame. The motorcycle further includes a front wheel rotatably mounted to the steering assembly. The motorcycle also includes a swingarm pivotably mounted to at least one of the engine/transmission assembly and frame, a rear wheel rotatably mounted to the swingarm, and a flexible drive member coupling the engine/transmission assembly and rear wheel such that the rear wheel is rotated in response to operation of the engine/transmission assembly.
The swingarm preferably includes a hollow portion adapted to contain oil for use in the engine/transmission assembly. At least one conduit communicates between the hollow portion of the swingarm and the engine for the flow of fluid, such as oil or oil-laden air, therebetween. The swingarm preferably defines an opening communicating with the hollow portion, and includes a plate mounted to the swingarm to cover the opening. The plate defines at least one port, and the conduit communicates between the at least one port and the engine/transmission assembly. The at least one conduit may include, for example, a breather tube for the flow of oil-laden air between the engine and the hollow portion of the swingarm.
There is at least one containment wall within the hollow portion of the swingarm. The containment wall defines a boundary of an oil sump within the hollow portion, and functions to contain oil within the oil sump. The oil sump is preferably defined substantially entirely within the front portion of the swingarm.
The swingarm preferably includes first and second sides extending along opposite sides of the rear wheel. The first side defines a drive member aperture therethrough, and a portion of the drive member extends through the drive member aperture. The drive member aperture is closed during normal operation of the motorcycle, but the swingarm includes a removable portion that is removable from the swingarm to open the drive member aperture.
The swingarm preferably includes at least one substantially fixed-position caliper mounting boss. A rear wheel caliper may be mounted to the mounting boss such that the rear wheel caliper is positioned to selectively clamp onto a portion of a brake rotor. The fixed-position caliper mounting boss is preferably located on a surface of the swingarm facing the rear wheel. Further, the rear wheel axle is preferably supported by the swingarm to maintain a substantially constant spacing between the rear wheel axle and the rear wheel caliper.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.